Electrode sensors are generally used to collect electrophysiological signals of patients in a wide variety of electrophysiological testing applications. Electroencephalography (EEG), electrooculography (EOG), electromyography (EMG), facial electromyography (fEMG), electroretinography (ERG), and visual electrophysiology (VEP) are a few examples of electrophysiological testing applications in which electrode sensors are used. In these examples of electrophysiological testing applications, the electrode sensors can collect electrophysiological signals produced from a body structure or structures that are the focus of the particular testing application. For example, in EEG, electrode sensors can collect electrical signals from skin locations adjacent to defined brain locations in response to a stimulation. In EOG, electrode sensors can collect electrical signals from skin locations adjacent eye muscles in response to visual stimuli. In EMG, electrode sensors can collect electrical signals from skin locations adjacent skeletal muscles in response to nervous stimulation. In fEMG, electrode sensors can collect electrical signals from skin locations adjacent facial muscles in response to a stimulation. In ERG, electrode sensors can collect electrical signals from conjunctival, corneal, or skin locations adjacent the retina in response to visual stimuli. Additionally, in VEP, electrode sensors can collect electrical signals from skin locations adjacent the visual cortex in response to visual stimuli. In all of these examples, the electrical signals generated from the various body structures are typically in the micro-volt range with some as small as fractions of a micro-volt. Generally, after some averaging and signal processing, the timing and amplitudes of the electrical signals can be used to monitor and assess the function or dysfunction of particular patient body functions.
A number of electrode sensors are currently available that can be used to collect electrophysiological signals for testing applications such as EEG, EOG, EMG, fEMG, ERG, and VEP. A disposal snap skin electrode is one example of an electrode sensor that is used in electrophysiological testing applications. A disposal snap skin electrode is generally round, oval, or rectangular in form, composed typically of non-conductive, non-woven fabric or synthetic material, and is very low cost.